Highly efficient power supply unit and method for supplying power using same

ABSTRACT

A more efficient power supply unit and a method for supplying power using same are disclosed. The power supply unit comprises a relay for switching alternating current power supplied from a plurality of sources; a direct current power supply for converting the switched current power to direct current power; and a controller for generating a switch signal to control the relay to switch the sources on the basis of the result for monitoring the alternating current power supplied from the sources.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/378,054, filed Aug. 11, 2014, which is a National Phase ofPCT/KR2013/000389, filed on Jan. 18, 2013, which claims priority under35 USC § 119 to Korean Patent Application No. 10-2012-0017848, filed onFeb. 22, 2012 and Korean Patent Application No. 10-2013-0000219, filedon Jan. 2, 2013, in the Korean Intellectual Property Office (KIPO), theentire contents of each of which are incorporated by reference herein intheir entirety.

TECHNICAL FIELD

Example embodiments relate to a highly efficient power supply device forsupplying power to a rack and a power supply method using the same.

BACKGROUND ART

Recently, with the emergence of a large data center, research is ongoingto convert a data center based on an alternating current (AC) powertransfer to a data center based on a more efficient direct current powertransfer.

In this regard, Korean Patent Laid-Open Publication No. 10-2011-003035,published on Jan. 11, 2011, titled “Direct current (DC) electric powersupply system”, discloses technology in which a DC power supply systemreceives AC power and directly supplies, to a plurality of servers, DCpower output from a rectifier configured to generate the DC power.

However, the conventional power supply system uses an individual powersupply unit (PSU) for each server. Accordingly, when an error occurs insupplying power due to, for example, an overload, a blackout, the faultof a PSU, it may critically affect a server operation. Also, the powerefficiency may vary based on a state of a PSU individually used for eachserver and thus, it may be difficult to achieve the maximum effect.

Accordingly, there is a need for a method that may prevent a data lossfrom occurring due to, for example, an overload, a blackout, and thefault of a PSU, and may maintain the power efficiency to be in anoptimal state.

SUMMARY

Some example embodiments provide a more efficient power supply devicethat may reduce or prevent a data loss from occurring due to, forexample, the fault of a power supply unit (PSU), a blackout, and anoverload, and a power supply method using the same.

Some example embodiments also provide a more efficient power supplydevice that may more efficiently supply power by decreasing an amount ofpower unnecessarily used, and a power supply method using the same.

Some example embodiments also provide a more efficient power supplydevice that may more effectively reduce or prevent a voltage dropphenomenon occurring in response to switching input voltage, and a powersupply method using the same.

Some example embodiments also provide a more efficient power supplydevice that may reduce a management and maintenance cost, and a powersupply device using the same.

Some example embodiments also provide a more efficient power supplydevice that may supply auxiliary power for a relatively long period oftime compared to a period of time maintained in an existing PSU, and apower supply method using the same.

Accordingly, there is a need for a method that may prevent a data lossfrom occurring due to, for example, an overload, a blackout, and thefault of a PSU, and may maintain the power efficiency to be in anoptimal state.

According to some example embodiments, there is provided a power supplydevice, including a relay configured to switch alternating current (AC)power supplied from a plurality of sources, a direct current (DC) powersupply configured to convert the switched AC power to DC power, and acontroller configured to generate a switch signal so as for the relay toswitch the sources based on a result of monitoring the AC power suppliedfrom the sources.

According to some example embodiments, the power supply device mayfurther include a monitoring unit configured to monitor the AC powerinput from the sources.

According to some example embodiments, the controller may switch asupply of the AC power from a first source to a second source whenunstable AC power is input from the first source for a predetermined ordesired period of time or more, and may switch the supply of the ACpower from the second source to the first source when the unstable ACpower is input from the second source for the predetermined or desiredperiod of time or more.

According to some example embodiments, the controller may switch thesupply of the AC power to any one of the first source and the secondsource and then maintain a switched state for a predetermined or desiredperiod of time, and may switch the supply of the AC power to an originalstate when normal AC power is input from a source from which theunstable AC power is input.

According to some example embodiments, the power supply device mayfurther include an instantaneous power supply configured to reduce orprevent an occurrence of a voltage drop phenomenon by supplying the DCpower to the plurality of servers when switching a supply of the ACpower.

According to some example embodiments, the instantaneous power supplymay include at least one of a capacitor and a lithium (Li) polymerbattery.

According to some example embodiments, the instantaneous power supplymay block an effect against the DC power being supplied, using at leastone of a diode and a field effect transistor (FET) in the case ofcharging.

According to some example embodiments, the DC power supply may beconnected with a plurality of power supply units (PSUs) in parallel.

According to some example embodiments, the power supply device mayfurther include a remote power monitoring unit configured to monitor anoperating state of each of the servers, and to activate or inactivateeach of the plurality of PSUs based on the operating state of thecorresponding server.

According to some example embodiments, the power supply device mayfurther include an integrator configured to integrate and distribute theDC power to be supplied to a plurality of servers included in a rack.

According to some example embodiments, the power supply device mayfurther include an interface board provided in each of the plurality ofservers to supply the distributed DC power to the corresponding server.

According to some example embodiments, the interface board may includean inrush current prevention circuit configured to prevent an occurrenceof a voltage drop phenomenon by inrush current occurring in the serverswhen applying initial power to the servers.

According to some example embodiments, there is provided a power supplymethod, the method including switching AC power supplied from aplurality of sources, converting the switched AC power to DC power, andgenerating a switch signal so as for the relay to switch the sourcesbased on a result of monitoring the AC power supplied from the sources.

According to some example embodiments, it is possible to reduce orprevent a data loss from occurring due to, for example, the fault of apower supply unit (PSU), a blackout, and an overload by multiplexingalternating current (AC) power supplied from a plurality of sources, byconverting the AC power to direct current (DC) power, by supplying theDC power based on a rack unit disposed in a data center, and by in thisinstance, monitoring the AC power being supplied, and by switching asource supplying the AC power based on a monitoring result.

According to some example embodiments, it is possible to reduce anamount of power unnecessarily used and to maintain the power efficiencyto be at a higher or maximum value at all times by monitoring anoperating state of each server using a remote power monitoring unit, andby selectively activating or inactivating each of a plurality of PSUsbased on the operating state of the corresponding server.

According to some example embodiments, it is possible to moreeffectively reduce or prevent a voltage drop phenomenon occurring inresponse to switching input power by supplying charged DC power whenswitching the input power.

According to some example embodiments, it is possible to reduce amanagement cost and/or maintenance cost and to complete charging fasterusing a semi-permanently available charging material.

According to some example embodiments, it is possible to supplyauxiliary power for a relatively long period of time compared to aperiod of time maintained in an existing PSU by supplying the auxiliarypower to each server using an interface board provided in each server tosupply DC power to the corresponding server.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a power supply device accordingto some example embodiments.

FIG. 2 is a diagram describing a power supply device according to someexample embodiments in more detail.

FIG. 3 is a diagram illustrating a detailed configuration of a powersupply device according to some example embodiments in more detail.

FIG. 4 is a diagram illustrating a switching a supply of power from afirst source to a second source when unstable power is input from thefirst source according to some example embodiments in more detail.

FIGS. 5 and 6 are circuit diagrams illustrating an instantaneous powersupply according to some example embodiments in more detail.

FIG. 7 is a graph showing a load amount of direct current (DC) power andoperation capacity of alternating current (AC) power according to someexample embodiments in more detail.

FIG. 8 is a diagram describing a process of supplying DC power from apower supply device to a plurality of servers included in a rackaccording to some example embodiments in more detail.

FIG. 9 is a diagram describing a process of supplying DC power from apower supply device to a plurality of servers included in a rackaccording to some example embodiments in more detail.

FIG. 10 is a diagram illustrating an example of a state in which a powersupply device is installed in a rack according to some exampleembodiments in more detail.

FIG. 11 is a perspective view illustrating a power supply deviceaccording to some example embodiments in more detail.

FIG. 12 is a circuit diagram illustrating an interface board accordingto some example embodiments in more detail.

FIG. 13 is a perspective view illustrating an interface board accordingto some example embodiments in more detail.

FIG. 14 is a flowchart illustrating a power supply method according tosome example embodiments in more detail.

DETAILED DESCRIPTION

Hereinafter, some example embodiments will be described in detail withreference to the accompanying drawings.

FIG. 1 is a block diagram illustrating a power supply device accordingto some example embodiments in more detail.

A power supply device 100 may supply stable direct current (DC) powerbased on a rack unit disposed in a data center, and may also maintainthe power efficiency to be in an improved or optimal state. Referring toFIG. 1, the power supply device 100 may include a monitoring unit 110, arelay 120, a DC power supply 130, and/or a controller 140.

When unstable power is supplied to a rack due to, for example, anoverload and a blackout, data recorded in a server may be lost. Toprevent this, the power supply device 100 may receive alternatingcurrent (AC) power from a plurality of sources, may multiplex thereceived AC power, may convert the multiplexed AC power to DC power, andmay supply the converted DC power to a plurality of racks.

As an example, high voltage AC power may be input from a first sourceand a second source to the power supply device 100. The power supplydevice 100 may selectively switch ON or OFF the AC power input from thefirst source and the second source using the relay 120, and maymultiplex the input AC power using a switching method.

The monitoring unit 110 monitors the AC power input to the power supplydevice 100. For example, the monitoring unit 110 may sense each ofvoltage and current of the AC power input from the first source andvoltage and current of the AC power input from the second source, andmay transmit a sensing value to the controller 140.

The relay 120 switches a supply of the AC power input to the powersupply device 100 to any one of the first source and the second source,based on a switch signal transmitted from the controller 140. The relay120 may be, for example, a solid state relay (SSR).

The DC power supply 130 converts, to DC power, the AC power multiplexedand thereby supplied through the relay 120, and supplies the convertedDC power to a plurality of servers. As an example, the DC power supply130 may convert, to 12V/100 A of DC power, 220V of AC power supplied tothe power supply device 100. The DC power supply 130 may include aplurality of power supply units (PSUs) configured to convert thesupplied AC power to the DC power. The PSUs may be connected in parallelto supply the DC power based on a rack unit.

As an example, when twenty servers each having the power capacity of 20A are included in a single rack, the rack requires a total of 400 Apower capacity. Accordingly, when operating the twenty servers includedin the single rack, the DC power supply 130 may include five PSUsconfigured to provide 200 A of DC power capacity. Accordingly, althoughany one of the five PSUs malfunctions, the DC power supply 130 maysupply 400 A of DC power capacity using the remaining four PSUs, therebyenabling the power to be more efficiently supplied to the rack.

The controller 140 generates a switch signal for switching a supply ofthe AC power to any one of the first source and the second source basedon a monitoring result received from the monitoring unit 110, andtransmits the switch signal to the relay 120. As an example, whenunstable AC power is input from the first source for a predetermined ordesired period of time or more, for example, 50 ms or more, thecontroller 140 may switch a supply of the AC power from the first sourceto the second source. Similarly, when unstable AC power is input fromthe second source for a predetermined or desired period of time or more,the controller 140 may switch the supply of the AC power from the secondsource to the first source.

According to some example embodiments, the controller 140 may include afunction of monitoring AC power supplied from a plurality of sources tothe power source device 100 to switch the supply of the AC power to anyone of the first source and the second source based on the monitoringresult.

When the supply of the AC power is switched by the controller 140,instantaneous input voltage is blocked and an operation of a PSU issuspended whereby a voltage drop phenomenon, for example, a dipphenomenon occurs in output power. To reduce or prevent this, the powersupply device 100 may further include an instantaneous power supply (see350 of FIG. 3) configured to supply DC power to the plurality of serversincluded in a rack when switching the supply of the AC power.

As an example, the instantaneous power supply may include at least oneof a capacitor and a lithium (Li) polymer battery. In some exampleembodiments, the instantaneous power supply may supply DC power chargedin the capacitor or the Li polymer battery when switching the supply ofthe AC power. When charging, for example, the capacitor or the Lipolymer battery, it may affect DC power to be supplied to a PSU. Toreduce or prevent this, the instantaneous power supply may use at leastone of a diode and a field effect transistor (FET).

The controller 140 may maintain the switched state for a predeterminedor desired period of time, for example, five to ten minutes afterswitching the supply of the AC power, and may monitor the AC power beingsupplied. When normal AC power is input from a source from whichunstable AC power has been supplied as the monitoring result, thecontroller 140 may also switch a supply of power to an original stateagain.

The DC power supplied from the DC power supply 130 may be integrated anddistributed through an integrator (see 360 of FIG. 3), and may besupplied to each server through connection to a corresponding interfaceboard (see 820 of FIG. 8). The interface board may reduce or prevent avoltage drop phenomenon by inrush current occurring in a server whenapplying initial power to the server, and may be applied to an existingDC power transfer based data center. As an example, the interface boardaccording to some example embodiments may be configured in a detachableform, for example, a module and may be combined in a space in which aPSU is absent from an existing server.

The power supply device 100 may further include a remote powermonitoring unit configured to monitor an operating state of each of theplurality of servers included in the rack, and to activate or inactivateeach of the plurality of PSUs included in the DC power supply, based onthe operating state of the corresponding server. The remote powermonitoring unit may include a camera, a temperature sensor, and thelike, to remotely monitor an operating state, an output state, and thelike of a server.

FIG. 2 is a diagram describing a power supply device according to someexample embodiments in more detail. Hereinafter, an example in whichfirst AC power and second AC power are input from two sources will bedescribed with reference to FIG. 2.

The monitoring unit 110 may sense the first AC power using a firstcurrent transformer (C/T) configured to sense voltage and current of thefirst AC power and may sense the second AC power using a second C/Tconfigured to sense voltage and current of the second AC power, and maytransmit sensing values to the controller 140.

When all of the first AC power and the second AC power are monitored asbeing stable as the monitoring result, the first AC power and the secondAC power may be supplied to the DC power supply 130 through the relay120.

Referring to FIG. 2, the DC power supply 130 may include a plurality ofPSUs, for example, first through eighth PSUs. The plurality of PSUs isconnected in parallel to uniformly distribute power and thus, it ispossible to reduce or minimize heat emission and to reduce or prevent anerror from occurring due to the fault of a PSU. Also, an existing powersupply device is configured to independently operate by applying ACpower to an individual PSU of each server and thus, a data loss mayoccur in a server in response to an input of unstable power. However,the power supply device according to some example embodiments may supplythe first AC power and the second AC power from different sources to therespective PSUs through the relay 120 and thus, may control the relay120 to switch a supply of input power so that stable power may besupplied, when unstable power is applied, due to a blackout, forexample.

To this end, the relay 120 may include, for example, first throughfourth relays and ninth through twelfth relays configured to switch thefirst AC power, and fifth through eighth relays and thirteenth throughsixteenth relays configured to switch the second AC power. The relay 120may switch a supply of the AC power to be supplied to the DC powersupply unit to any one of the first source and the second source, basedon a switch signal transmitted from the controller 140.

The controller 140 may monitor the first AC power and the second ACpower to be supplied to the DC power supply 130 based on sensing valuesreceived from the monitoring unit 110. The controller 140 may controlonly the second AC power to be supplied to the DC power 130 supply byswitching the first through fourth relays and the ninth through twelfthrelays when the first AC power is unstable, and may control only thefirst AC power to be supplied to the DC power supply 130 by switchingthe fifth through eighth relays and the thirteenth through sixteenthrelays when the second AC power is unstable.

The controller 140 may continuously monitor the first AC power and thesecond AC power in a state in which the input voltage is switched. Whennormal AC power is input from a source from which unstable AC power hasbeen input, the controller 140 may switch an input of the AC power to anoriginal state to make it possible to receive a self-voltage. Thecapacitor or the Li polymer battery having supplied the DC power mayhave a charging time in order to reduce or prevent an occurrence of avoltage drop phenomenon, for example, a dip phenomenon and thus, thecontroller 140 may switch the input of the AC power to an original stateat a delay of about 30 seconds.

FIG. 3 is a diagram illustrating an example detailed configuration of apower supply device according to some example embodiments of the presentinvention, and FIG. 4 is a diagram illustrating a switching a supply ofpower from a first source to a second source when unstable power isinput from the first source according to some example embodiments inmore detail.

When unstable power is supplied due to, for example, an overload and/ora blackout, data recorded in a server may be lost. Accordingly, toprevent this, the power supply device may be supplied with multiplexedAC power from different sources. FIG. 3 illustrates an example in whichinput power is duplexed into first AC power and second AC power.

When first AC power and second AC power are supplied, the monitoringunit 110 senses voltage and current of the first AC power using a firstC/T 310 and senses voltage and current of the second AC power using asecond CIT 320, and transmits sensing values to the controller 140.

Referring to FIG. 3, the relay 120 includes a plurality of SSRs, forexample, first through sixteenth relays, and transfers the first ACpower and the second AC power to the respective PSUs, for example, firstthrough eighth PSUs included in the DC power supply 130. Although FIG. 3illustrates an example in which the first AC power is supplied to thefirst through eighth PSUs using the first through fourth relays and theninth through twelfth relays and the second AC power is supplied to thefirst through eighth PSUs using the fifth through eighth relays and thethirteenth through sixteenth relays, the number of relays and the numberof PSUs may be modified based on necessity.

When all of the first AC power and the second AC power are stable, thefirst AC power and the second AC power may be supplied to the DC powersupply 130 as illustrated in a part (a) of FIG. 4. However, when thefirst power supply is unstable, the first through fourth relays and theninth through twelfth relays may switch a supply of AC power to besupplied to the DC power supply 130 from the first AC power to thesecond AC power based on a switch signal of the controller 140.

To this end, the controller 140 may generate a switch signal forswitching the supply of the AC power to any one of the first source andthe second source based on sensing values received from the monitoringunit 110, and may transmit the switch signal to a corresponding relay.

As an example, when unstable AC power is input from the first source fora predetermined or desired period of time or more, for example, 50 ms ormore, the controller 140 may switch the supply of the AC power from thefirst source to the second source. Similarly, when unstable AC power isinput from the second source for the predetermined or desired period oftime or more, the controller 140 may switch the supply of the AC powerfrom the second source to the first source.

When the supply of the AC power is switched by the controller 140,instantaneous input voltage is blocked and an operation of a PSU issuspended whereby a voltage drop phenomenon, for example, a dipphenomenon occurs in output power. To reduce or prevent this, theinstantaneous power supply 350 supplies DC power to a rack whenswitching the AC power being supplied to the DC power supply 130. As anexample, the instantaneous power supply 350 may supply, to a rack, DCpower charged in a capacitor or a Li polymer battery when switching theAC power being supplied to the DC power supply 130.

The instantaneous power supply 350 may include a rectifier circuitconfigured to rectify the duplexed AC power to DC power and a constantvoltage circuit configured to maintain the rectified DC power to be atconstant voltage. Also, not to affect a PSU when charging the capacitoror the Li polymer battery, the instantaneous power supply 350 mayinclude a diode or a FET. Accordingly, although an error occurs in anyone input AC power, the instantaneous power supply 350 may charge thecapacitor or the Li polymer battery with normal power. As describedabove, separate power may be used instead of charging the capacitor orthe Li polymer battery with the DC power. When the charging materialapplies initial power to the PSU, the initial power of the chargingmaterial has a short value. Therefore, a power output of the PSU isinstantaneously shorted when the initial power is applied to PSU, andthe power output of the PSU is not normally outputted. To avoid this,the instantaneous power supply 350 may charge the charging material withthe AC power up to a predetermined or desired level by employing anelectrical switch between the charging material and a PSU output, andenables the charging material to interact with an output by connecting aswitch when it is beyond the predetermined or desired level.

The controller 140 may maintain the efficiency of the power supplydevice to be at a higher or maximum value at all times by monitoringstates of the first through eighth PSUs included in the DC power supply130 using a third C/T 330 and by activating or inactivating each PSUbased on server operation capacity. The controller 140 may controlinformation on the first AC power, the second AC power, and the firstthrough eighths PSUs to be displayed on a display 340 connected to thecontroller 140. Also, the controller 140 may transmit information on thefirst AC power, the second AC power, and the first through eighth PSUsto a remote power monitoring device, or may receive a switch signal fromthe remote power monitoring device.

When AC power being supplied to the DC power supply 130 is switched, thecontroller 140 may maintain the switched state for a predetermined ordesired period of time, for example, five to ten minutes and may monitorthe AC power supplied from the AC power supply. When normal AC power isinput from a source from which unstable AC power has been input as themonitoring result, the controller 140 may switch the supply of power toan original state.

DC power supplied from the DC power supply 130 may be integrated throughthe integrator 360 and may be supplied to each server installed in arack.

A power supply device according to the related art may employ individualpower for each server and thus, may affect a server operation when anerror occurs in a PSU. Also, the efficiency of a PSU may vary based on astate of the individually used PSU and thus, it may be difficult toachieve an improved or maximum effect. However, as described above, thepower supply device according to some example embodiments enables powerto be more uniformly distributed by employing a plurality of PSUs, forexample, the first through the eighth PSUs in parallel and thus, it ispossible to reduce or minimize heat emission and to reduce or prevent anerror from occurring due to the fault of a PSU. Also, it is possible tomaintain the power supply device to be in an improved or optimal stateat all times by activating or inactivating each PSU based on anoperating state of a server using a remote power monitoring unit.

Also, the power supply device according to the related art may beconfigured to independently operate by applying AC power to anindividual PSU of each server and thus, there is no measure for unstableinput power. However, the power supply device according to some exampleembodiments may supply two input powers, for example, the first AC powerand the second AC power, from different sources to the respective PSUsthrough the relay 120. Accordingly, when unstable power is applied dueto, for example, a blackout, the power supply device according to someexample embodiments may switch a supply of input power so that stablepower may be supplied, based on a switch signal transmitted from thecontroller 140 or the remote power monitoring unit. Also, the powersupply device may monitor the input power while maintaining the switchedstate for a predetermined or desired period of time, for example, fiveto ten minutes and may switch the supply of power to an original stateagain when normal power is supplied from a source in which the error hasoccurred.

The instantaneous power supply 350 may include a Li polymer battery or acapacitor to instantaneously supply DC power in response to switchingthe input power. In the case of supplying the DC power using a generalbattery, a periodic check may be required due to a volume issue and adecrease in a lifespan by charging/discharging or natural discharging.When a predetermined or desired period of time has elapsed, managementand/or maintenance costs may increase. Also, due to a characteristic ofthe general battery, the general battery has nominal voltage. Thus, whencharging the battery voltage up to the nominal voltage, a lifespan ofthe battery may be reduced. When fully charging the battery voltage, thebattery voltage may be instantaneously discharged even up to the nominalvoltage due to an occurrence of a dip phenomenon, which may lead toresetting a server. Accordingly, by employing a semi-permanentlyavailable capacitor, it is possible to reduce management cost and/ormaintenance cost, and to readily use the capacitor up to the chargedvoltage. In addition, a relatively short charging time may be neededcompared to a general battery.

Also, the power supply device according to some example embodiments mayperform real-time management using a controller or a remote powermonitoring unit, may reduce an amount of power unnecessarily used byactivating or inactivating each PSU based on a server capacity, and/ormay distribute load against input by monitoring input voltage or currentand by switching the input power using a relay when the input voltage isunstable, and by monitoring the input voltage for a predetermined ordesired period of time after switching and by switching a supply ofpower to an original state when the input power is restored to benormal.

FIG. 5 is a circuit diagram illustrating an instantaneous power supplyaccording to some example embodiments, FIG. 6 is a circuit diagramillustrating a detailed configuration of the instantaneous power supply,and FIG. 7 is a graph showing a load amount of DC power and operationcapacity of AC power according to some example embodiments of thepresent invention.

As an example, as illustrated in FIG. 5, the instantaneous power supply350 may include super capacitors connected in series, and may also beconfigured to include a detachable package that is divided based onpredetermined or desired capacity for an easy replacement depending on anecessity. When output voltage is higher than self-voltage strength, asuper capacitor combust (or arc) and thus, the super capacitors may beconnected in series to have the self-voltage strength higher than theoutput voltage. The instantaneous power supply 350 may include a diodeor a FET 510 to reduce or prevent a PSU from being affected whencharging the super capacitor.

Also, referring to FIG. 5, the instantaneous power supply 350 mayinclude, at a front end, a separate rectifier circuit configured tocharge the super capacitor with DC power, a rectifier circuit configuredto rectify duplexed AC power to DC power, and a constant voltagecircuit. Accordingly, although an error occurs in any one input ACpower, the instantaneous power supply 350 may charge the super capacitorwith the normal power. As described above, separate power may be usedinstead of charging the super capacitor with the DC power. It is becausea characteristic of the super capacitor having a short value whenapplying initial power may cause a PSU power output to beinstantaneously shorted and thereby not be normally output when anoutput is immediately connected. To avoid this, the instantaneous powersupply 350 may charge the super capacitor with the AC power up to apredetermined or desired level by employing an electrical switch betweenthe super capacitor and a PSU output, and enables the super capacitor tointeract with an output by connecting a switch when it is beyond thepredetermined or desired level.

When input power is switched, a load amount instantaneously rises asshown in an area D of the graph of FIG. 7 and thus, a dip phenomenonoccurs. To avoid this, when switching the input power, an instantaneouspower supply may instantaneously supply DC power charged in a battery ora capacitor, instead of a DC power supply.

FIG. 8 is a diagram describing a process of supplying DC power from apower supply device to a plurality of servers included in a rackaccording to some example embodiments of the present invention.

220V of AC power input from a plurality of sources to the power supplydevice 100 may be multiplexed and be supplied to the DC power supply 130through the relay 120. The relay 120 may selectively control ON/OFF of aplurality of AC power inputs, or may multiplex an input of AC powerusing a switching method.

The DC power supply 130 converts, to DC power, AC power supplied throughthe relay 120. As an example, the DC power supply 130 may convert the ACpower to about 12V/100 A of DC power. The DC power supply 130 mayinclude a plurality of PSUs configured to convert the AC power to the DCpower.

The integrator 360 may integrate the DC power converted by the DC powersupply 130. As an example, the integrator 360 may be connected with theDC power supply 130 through a bus bar that is a conductor fortransferring power. To stably supply the power, the integrator 360 maydistribute the DC power supplied from the DC power supply 130 as the DCpower within about 24V or of 12V.

At least one server 810 supplied with the DC power through theintegrator 360 may be included in a rack 800. Referring to FIG. 8, eachserver 810 may be connected to the power supply device 100 through acorresponding interface board 820.

The interface board 820 is configured to supply, to the at least oneserver 810, the DC power supplied through the integrator 360, and maysimplify a connection line such as a cable. The integrator 360 and theinterface board 820 may be directly connected using a one-to-one cable.

Also, the interface board 820 may include an inrush current preventioncircuit and thus, may reduce or prevent an occurrence of a voltage dropphenomenon by inrush current occurring in the at least one server 810when applying initial power. The interface board 820 may also be appliedto an existing DC power transfer based server.

The interface board 820 may include a noise removal circuit.

As an example, the power supply device 100 according to some exampleembodiments may supply DC power to each of the plurality of servers 810included in the rack 800 by employing the appropriate interface board820 for each server 810. For example, the power supply device 100according to some example embodiments may directly supply the DC powereven to a general server by using the interface board 820. Accordingly,various types of servers 810 may be added to the rack 800.

A rear surface of the interface board 820 may include an insulator (notshown) of epoxy base and the like. The insulator of the interface board820 may function as a type of cover capable of insulating high currentand may function to guide the interface board 820 to be connected to aninner main board (not shown) of the server 810, thereby enabling a safeand accurate connection of the interface board 820.

The power supply device 100 according to some example embodiments mayinclude an instantaneous power supply (see 350 of FIG. 3). As describedabove, the instantaneous power supply may be configured using supercapacitors connected to the DC power supply 130. The instantaneous powersupply 350 may be charged with DC power and may supply power to eachserver 810 in the case of an emergency.

For example, the instantaneous power supply may avoid a dip phenomenonby not immediately responding to an instantaneous change in the DC powersupply that occurs due to instantaneous rise in a load amount of the DCpower supply 130 and by slowly responding to the change after apredetermined or desired delay. The instantaneous power supply maysupply the DC power to the interface board 820, thereby enabling thestable power supply to be secured.

Also, the instantaneous power supply may supply the DC power in responseto an instantaneous blackout occurring due to a switching time delay.Due to an error occurring in any one AC power supplied from a pluralityof sources, the switching time delay may occur when switching a supplyof the AC power from a corresponding source to another source thatsupplies stable AC power. That is, when an error such as aninstantaneous blackout occurs in supplying power, the instantaneouspower supply may instantaneously supply the power to the at least oneserver 810 to respond to the emergency, thereby enabling the power to bestably supplied.

FIG. 9 is a diagram describing a process of supplying DC power from apower supply device to a plurality of servers included in a rackaccording to some example embodiments of the present invention.

Referring to FIG. 9, the power supply device may include a supply 910, aconverter 920, and a distribution unit 930.

The supply 910 supplies at least one AC power. For example, the supply910 may supply 220V of AC power. Although not illustrated in detail, thesupply 910 may be configured to multiplex and thereby supply the ACpower. In some example embodiments, the supply 910 may selectivelycontrol ON/OFF of a plurality of AC power inputs, or may multiplex theplurality of AC power inputs using a switching method.

The converter 920 converts, to DC power, the AC power supplied from thesupply 910. The converter 920 may convert the AC power to about 12V/100A of DC power. In some example embodiments, the converter 920 mayinclude a plurality of rectifiers 921 configured to convert the suppliedAC power to the DC power and an integrator 922 configured to integratethe converted AC power.

The distribution unit 930 distributes the DC power converted by theconverter 920 and controls applying of overcurrent. The distributionunit 930 may include a plurality of distributors 931, and may reduce orprevent distribution of the DC power in response to applying of theovercurrent when distributing the DC power using the plurality ofdistributors 931. The distribution unit 930 may be connected with theconverter 920 through a bus bar B that is a conductor to transferelectrical energy.

To stably supply the power, the DC power distributed from thedistribution unit 930 may be supplied to the rack 800 as power withinabout 24V or of 12V and about 18 A.

At least one server 810 configured to be supplied with the DC powerdistributed by the distribution unit 930 maybe included in the rack 800.For example, the number of servers 810 connected to each of tendistributors 931 included in the distribution unit 930 may be at theratio of two folds or more and thereby be supplied with the DC power.Referring to FIG. 9, two servers 810 are connected to a singledistributor 931 and thus, twenty servers 810 corresponding to tendistributors 931 are included in the rack 800.

Each server 810 may be connected to the power supply device through thecorresponding interface board 820. The interface board 820 may refer toa type of a connection device configured to supply the DC power suppliedfrom the power supply device to the at least one server 810 and maysimplify a connection line such as a cable.

The DC power is supplied from the distribution unit 930 to one side ofthe interface board 820. Although a portion that connects the interfaceboard 820 and the distribution unit 930 is not illustrated in detail, aconnector for high current and a fuse for reducing or preventingovercurrent may be provided. Another side of the interface board 820 maybe connected to a main board (not shown) of the at least one server 810to supply the power supplied from the distribution unit 930 to the atleast one server 810. The other side of the interface board may beprovided with a structure of a socket similar to a PSU of the at leastone server 810. Although not illustrated, a noise removal circuit may befurther included.

FIG. 10 is a diagram illustrating an example of a state in which a powersupply device is installed in a rack according to some exampleembodiments of the present invention, and FIG. 11 is a perspective viewillustrating a power supply device according to some example embodimentsof the present invention.

Referring to FIG. 10, a single power supply device 100 may be receivedin a single rack 800. As described above, the power supply device 100may include the relay 120, the DC power supply 130, the integrator 360,and the like. The integrator 360 may supply the DC power supplied fromthe DC power supply 130 to each server 810 included in the rack 800through the corresponding interface board 820.

The power supply device 100 may be positioned in an upper portion or acentral portion of the rack 800. As an example, when the power supplydevice 100 is positioned in a central portion of the rack 800, a voltagedrop of about 0.2V to 0.3V may occur between servers positioned at a topend and a bottom end among the plurality of servers 810 included in therack 800. To compensate for this, the DC power supply 130 may increasean output of DC power by about 0.3V.

When twenty servers 810 each having the power capacity of 20 A areincluded in a single rack 800, the rack 800 requires a total of 400 Apower capacity. Accordingly, when initially operating the twenty servers810, the twenty servers 810 may operate at about 80% of 500 Acorresponding to the capacity of DC power supplied from the DC powersupply 130. For example, in a case in which the DC power supply 130includes five PSUs configured to provide 200 A of DC power capacity,although any one of the five PSUs malfunctions, the remaining four PSUsmay provide 400 A of DC power capacity and thus, the power may be stablysupplied to the servers 810. In addition, when load of a single server810 among the plurality of servers 810 is assumed as about 12 A in anormal operating state, the twenty servers 810 require about 240 A of DCpower capacity. Accordingly, although the DC power supply 130 supplies400 A of DC power capacity, about 60% of load operation is enabled.Therefore, the power supply device according to some example embodimentsmay stabilize the power supply through the above configuration.

As an example, referring to FIG. 11, the power supply device accordingto some example embodiments may be configured as a single deviceembedded with the relay 120, the DC power supply 130, the controller140, the instantaneous power supply 350, and the like, and may be housedin a rack.

FIG. 12 is a circuit diagram illustrating an interface board accordingto some example embodiments of the present invention.

The interface board may supply DC power to a server and may also controlinrush current occurring in the server when applying initial power tothe server to occur at a reduced or minimum level, thereby reducing orpreventing an occurrence of a dip phenomenon by the inrush current andsupplying the stable power.

To this end, referring to FIG. 12, adding a switch to an input endenables cutting off power when an error occurs at a final output end.Also, it permits stably supplying auxiliary power, for example, 3.3V tothe server by adding a power converter.

A product connectible to a server may be applicable as a connector of aninterface board.

FIG. 13 is a perspective view illustrating an interface board accordingto some example embodiments.

Referring to FIG. 13, as an example, the interface board may include aninput unit 1310 configured to receive DC power from an external powersupply device converting AC power to the DC power and a supply 1320configured to supply the received DC power to a server included in arack, and may be directly connected to each server disposed based on arack unit instead of an existing PSU. The interface board may bedifferently manufactured based on DC capacity of the server and aconnection method with the server.

The interface board may include an inrush current preventer 1330configured to reduce or prevent an occurrence of a voltage dropphenomenon by inrush current occurring in the server when applyinginitial power to the server. In some example embodiments, the inrushcurrent preventer 1330 may include a fuse configured to reduce orprevent an input of current higher than the inrush current.

Also, although not illustrated in FIG. 13, the interface board mayinclude a switch configured to cut off the power when the current isinput through the supply 1320. In addition, the interface board mayinclude a power converter configured to convert, to a predetermined ordesired voltage, DC power supplied from an external power supply device,thereby enabling auxiliary power to be more stably supplied to theserver.

The interface board may include a bus bar 1340 for heat emission of aninrush current prevention circuit and a ground (GND) guarantee. The rearsurface of the interface board may be configured as an epoxy-basedelectro-thermal body. Also, a state indication light emitting diode(LED) configured to verify and adjust a power supply state of the servermay be included in the interface board.

FIG. 14 is a flowchart illustrating a power supply method according tosome example embodiments.

In operation 1410, a power supply device receives and multiplexes ACpower from a plurality of different sources to supply stable DC powerbased on a rack unit disposed in a data center and to maintain the powerefficiency to be in an improved or optimal state.

In operation 1420, a monitoring unit of the power supply device monitorsthe AC power supplied from the sources. As an example, when input powerof the power supply device is duplexed into first AC power and second ACpower, the monitoring unit may sense each of voltage and current of thefirst AC power and voltage and current of the second AC power, and maytransmit sensing values to a controller of the power supply device.

When the controller of the power supply device detects an occurrence ofa power error in the first AC power or the second AC power based on thesensing values received from the monitoring unit in operation 1430, thecontroller generates a switch signal for switching a supply of the ACpower to a normally operating source and transmits the switch signal toa relay, thereby enabling the AC power to be stably supplied inoperation 1440. The relay may switch the AC power supplied from an ACpower supply to any one of a first source and a second source. As anexample, the relay may be an SSR.

As an example, when unstable AC power is input from the first source fora predetermined or desired period of time or more, for example, 50 ms ormore, the controller of the power supply device may switch a supply ofthe AC power from the first source to the second source. Similarly, whenthe unstable AC power is input from the second source, the controller ofthe power supply device may switch the supply of the AC power from thesecond source to the first source.

When the supply of the AC power is switched, instantaneous input voltageis blocked and an operation of a PSU is suspended whereby a dipphenomenon occurs in output power. To reduce or prevent this, when thesupply of the AC power is switched, an instantaneous power supply of thepower supply device may supply, to a server, DC power charged in acapacitor or a Li polymer battery. When charging, for example, thecapacitor or the Li polymer battery, it may affect the DC power to besupplied to a PSU. Accordingly, to reduce or prevent this, theinstantaneous power supply may use at least one of a diode and a FET.

The controller may maintain the switched state for a predetermined ordesired period of time, for example, five to ten minutes after switchingthe supply of the AC power, and may monitor the AC power being suppliedfrom the AC power supply. When normal AC power is verified to be inputfrom a source from which the unstable AC power has been input as themonitoring result, the controller may switch a supply of power to anoriginal state again.

In operation 1450, the AC power supplied through the above process maybe converted to the DC power through a DC power supply and thereby besupplied to the plurality of servers included in a rack. The DC powersupply may include a plurality of PSUs configured to convert the ACpower being supplied to the DC power. The PSUs may be connected inparallel to supply the DC power to the plurality of servers.

The DC power supplied from the DC power supply may be integrated anddistributed through an integrator, and thereby be supplied to theplurality of servers included in a rack. An interface board thatconnects the power supply device and a server may reduce or prevent anoccurrence of a voltage drop phenomenon by inrush current occurring inthe server when applying initial power to the server, thereby supplyingpower to each constituent element of the server. The interface board mayalso be applicable to an existing DC power transfer based server.

An operating state of each of the plurality of servers included in therack may be monitored using a remote power monitoring unit. The remotepower monitoring unit may activate or inactivate each of the pluralityof PSUs included in the DC power supply based on the operating state ofthe corresponding server.

Although some example embodiments have been shown and described, thepresent invention is not limited to the described example embodimentsand those skilled in the art may make various changes and modificationsfrom the description. Accordingly, the scope of the present invention isnot limited to the described example embodiments and is defined by theclaims and their equivalents.

What is claimed is:
 1. A power supply device, comprising: a plurality of relays each configured to switch alternating current power supplied from a plurality of sources; a direct current power supply configured to, receive the switched alternating current power supplied by at least two of the plurality of relays, and convert the switched alternating current power to direct current power; and a controller configured to generate a switch signal to control the plurality of relays to switch the sources based on a result of monitoring the alternating current power supplied from the plurality of sources, wherein the direct current power supply includes a plurality of power supply units (PSUs) each being connected to each other in parallel, each of the plurality of PSUs being connected to all of the plurality of sources, and wherein the controller is configured to switch a supply of the alternating current power from a first source to a second source when unstable alternating current power is received from the first source for a desired period of time or more, and switch the supply of the alternating current power from the second source to the first source when the unstable alternating current power is received from the second source for the desired period of time or more.
 2. The power supply device of claim 1, wherein the controller is further configured to: monitor the alternating current power input received from the plurality of sources using at least one sensor.
 3. The power supply device of claim 1, further comprising: an instantaneous power supply configured to prevent an occurrence of a voltage drop phenomenon by supplying the direct current power to a plurality of servers when switching a supply of the alternating current power.
 4. The power supply device of claim 1, further comprising: a remote power sensor configured to monitor an operating state of a plurality of servers, and to activate or inactivate each of the plurality of PSUs based on the operating state of the corresponding server.
 5. A power supply method of a power supply device, the method comprising: switching alternating current power supplied from a plurality of sources using a plurality of relays; receiving the switched alternating current power supplied by at least two of the plurality of relays using a direct current power supply including a plurality of power supply units (PSUs) each being connected to each other in parallel, each of the plurality of PSUs being connected to all of the plurality of sources; converting the switched alternating current power to direct current power using the direct current power supply; and generating a switch signal to control the plurality of relays to switch the sources based on a result of monitoring the alternating current power supplied from the sources using a controller, wherein the switching includes switching, using at least one relay of the plurality of relays, a supply of the alternating current power from a first source to a second source when unstable alternating current power is received from the first source for a desired period of time or more, and switching, using the at least one relay of the plurality of relays, the supply of the alternating current power from the second source to the first source when the unstable alternating current power is received from the second source for the desired period of time or more.
 6. The method of claim 5, further comprising: preventing an occurrence of a voltage drop phenomenon by supplying, to a plurality of servers, the direct current power.
 7. The method of claim 5, further comprising: monitoring an operating state of each of a plurality of servers using at least one remote power monitoring sensor; and activating or inactivating each of the plurality of PSUs based on the operating state of the corresponding server and supplying the direct current power to the plurality of servers. 